- Water is polar. Polarity within a molecule is due to electronegativity differences between the molecule's atoms. Oxygen is more electronegative than hydrogen. Therefore, the electrons are pulled closer to the oxygen. This results in the oxygen becoming slightly negative and the hydrogen slightly positive. The polarity of water results in other physical properties of water, such as having a high specific heat capacity and surface tension.

- Water is one of the only substances on earth that is found in all three state (solid, liquid, and gas).

- Solid water (ice) is less dense than liquid water. Thus, ice floats. This is important in the survival of aquatic organism when it is cold enough outside for lakes and ponds to freeze.